The present invention relates to a method for producing sulfur plates.
Conventionally, owing to the low cost and its high mechanical strength, cement concrete has been popularly used in the field of civil engineering and construction engineering.
Cement concrete, however, exhibits a poor resistance to acid due to the presence of cement therein and cannot be used for locations or structures where acid is used, for example, the floors or walls of factories producing foods or handling aggressive chemicals.
Furthermore, in a country like Japan where earth or soil is considerably acidic, the installation of cement concrete products such as U-shaped gutters is extremely difficult since the concrete readily collapses under such stronk acidic environment.
Accordingly, for resolving the above defects of normal concrete, the sulfur concrete was developed.
Such sulfur concrete comprises sulfur, inorganic powder such as fly ash or silica powder, sands and gravels. For producing such sulfur concrete, two producing methods are known, wherein in one method, the raw materials are first heated at a temperature of higher than 120.degree. C. and subsequently mixed and cast under heated condition. And in the other method, the raw materials are first mixed at an ambient temperature and subsquently put in a mold and heated and cast.
The sulfur concrete becomes hardened extremely faster than the conventional cement concrete and can acquire the desired strength in a shorter period than the conventional cement concrete. Accordingly, such sulfur concrete is especially convenient for the construction in the cold seasons or the cold districts which yet necessitates acid resistance.
However, in spite of the fact that the production of sulfur which is the major raw material for the sulfur concrete is considerably abundant in Japan, the cost per weight of the sulfur is twice to four times as high as the cost for the cement, and the civil engineering construction by sulfur concrete which requires a considerable amount of sulfur necessitates a tremendous construction cost and accordingly is not favorable in terms of economy.
Furthermore, since the sulfur concrete is neutral or slightly acidic, the conventional steel bars cannot be used for reinforcing the sulfur concrete and the constructions or structures built by using such sulfur concrete provided with said steel bars has given rise to problems in terms of the corrosion of the reinforcement.
Accordingly, it is an object of the present invention to provide a method for producing sulfur plates which can overcome the above defects of the conventional producing methods while minimizing an amount of sulfur as a raw material for producing such sulfur plates.